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Bed Plate and Brass Work.

XXXIV.    Bed Plate (Fig. 269).—This is not too large for
a planing machine such as was described at page  169.    It is
better to plane the under edge, so that the bed may rest more
perfectly on the stone or brickwork.    The casting is therefore set
upside down on the machine, and the ends clamped till the two
side edges are planed; the clamping is then removed to the side,
and the end edges planed with a short stroke.    The bed being
now set right way up, and held by its lower rim all round, must
next have its seating marked, so as to plane off the calculated
allowance (the total depth is not of any consequence).    All the
seatings will be done at once, with a stroke the whole length of
the table.    The bolt and stud holes are to be marked off by the

XXXV.    Brass Work (Fig. 270) must be bright all over
the exterior, and have the interior bored at certain after-mentioned
places.    The Oilcup at B can be finished entirely by chuck
turning and drilling, polishing with the very finest emery cloth.
The Cylinder Cock, A, is cored throughout.    The main body
and the plug socket are both turned externally as far as possible,
but the central portion must be finished with file, and the corners
cleaned with  a riffler.    The socket and plug are respectively
bored and turned in the manner shewn at Fig. 254, the cock
then placed in the vice, and the plug ground to fit, with fine
emery powder and water, by rotating backward and forward with
a wrench upon the shank.    The screws are chased, and the flange
drilled; and the whole polished with fine emery cloth.   The union
nut, after finishing, is slipped over the copper pipe, and the conical
nipple then brazed to the latter (see page 86).

The Sight-feed Lubricator, D, is the only form now used
for slide valve and piston lubrication. The oil-chamber, #, is
fixed in any convenient position, and two connections made with
the steam pipe as shewn. Having filled a with oil, and the sight-
feed b with water, the valves c and d are opened, as well as the
two steam cocks, and steam being condensed in the coiled pipe,
forms water, which enters a afnd displaces the oil, forcing it lip
through the glass sight-feed chamber drop by drop, it being seen
rising through the water in b, than which it is specifically lighter.
Reaching the steam pipe, it is carried by the steam to the slide